Effect

Generation I

Using 25% of its maximum HP, the user creates a substitute with 1 HP more than the amount of HP lost by the user. If the user's maximum HP is 3 or less, it will not lose any HP when the substitute is made. A substitute will have the same current type and current stats as the Pokémon that created it.

Once created, all stat modifying attacks and side effects of attacks used by the opponent against the user will fail, though all current stat modifiers will remain in effect and any stat modifiers used by the user will also be applied to the substitute. The substitute will break when the damage the substitute has taken is equal to or greater than the HP used to make it. Until it breaks, a substitute will absorb all damage done by the opponent (even if the damage done exceeds the remaining HP of the substitute), but will not reduce the actual amount of damage that the opponent's attacks do. A one-hit KO move, if it hits, will always break a substitute.

Substitute will not protect the user from self-inflicted status conditions, but it will protect it from any status condition generated by an opponent's move and damage due to those status conditions.

If a Pokémon breaks a substitute with Hyper Beam, it will not need to recharge. If a Pokémon breaks a substitute with Explosion or Selfdestruct, it will not faint, though its picture will no longer be visible until it switches out or uses Substitute. If a Pokémon breaks a substitute with a recoil move, it will not take any recoil damage. If a Pokémon breaks a substitute with a draining move, no HP will be restored to it. Note that in each of these cases, the substitute has to be broken, not merely damaged, by the referenced attack.

If the user's current HP is less than 25% (rounded down) of its maximum HP, it will be too weak to make a substitute. If the user's current HP is exactly equal to 25% (rounded down) of its maximum HP, it will faint upon creating the Substitute.

In Stadium, if the user's current HP is exactly equal to 25% (rounded down) of its maximum HP, it will be too weak to create a substitute. If a Pokémon breaks a substitute with Explosion or Selfdestruct, it will faint.

Generation II

If the user has a status condition, they will still take any damage from that status condition after they have used Substitute.

If the substitute is broken by a target's Self-Destruct or Explosion, the user of that move will faint. Breaking a substitute no longer prevents recoil damage.

If the user of Substitute has 25% or less of its max HP (rounded down), it will be unable to make a substitute.

A substitute can be Baton Passed, and can absorb damage from partial-trapping moves.

In other games

Substitute is a Special move for Greninja. The substitute it summons resembles those from the main games.

Sprites

This section is incomplete.Please feel free to edit this section to add missing information and complete it. Reason: Missing the substitute images from Generation VI (and Stadium, in case it's different from Stadium 2).

Trivia

A substitute "levitating"

A substitute in place of Masahiro Sakurai

In most games, the decoy and the Pokémon will switch places when the Pokémon executes a move. The only exception is in Pokémon Battle Revolution, where the battle animations play out as if the substitute was the one performing the move. It generally remains stationary, except when using moves like Fly or Bounce.

Shedinja can learn Substitute despite being incapable of using it, as its HP is too low to create a substitute.

Substitutes are interpreted differently throughout all forms of Pokémon canon. In the games, a substitute is seen as an inanimate decoy which simply stands in for the Pokémon. In the anime, substitutes are seen to be clones of the user. In the manga, substitutes are like the anime representation, but more spectral and transparent, as shown by Red's Pikachu in Peace of Mime.

In the Mystery Dungeon series, if the player eats an X-Eye Seed, all other Pokémon appear as substitutes.

In Pokémon Stadium, glitch Pokémon will appear as the substitutes. The color will vary, however, due to the player's ID and the glitch Pokémon's name. This is because the game treats the glitch Pokémon's name as a nickname, which cause Pokémon to change colors in the Stadium series.

In Generation VI, the size of the substitute depends on the size of the Pokémon using it. For example, a substitute made by a Kyurem will be bigger than that of a Flabébé.